Hair relaxers are used for permanent straightening of curly and/or kinky hair. Such products are used by women of African ancestry. The relaxer is typically an alkali which breaks the natural disulfide bonds within the hair. The user mechanically straightens the hair. Then the disulfide bonds are reformed in the straightened hair through neutralization of the active ingredient in the relaxer, which is often a strong alkali.
The alkali relaxers for which the neutralizing compositions and methods of the present invention are applicable include those comprising a strong alkali. The neutralizing compositions and methods contained within may also work on weak alkali, such as monoethanolamine, triethanolamine, and ammonium hydroxide, which may be used to lessen the degree of curl by weakening the disulfide bonds. These weak alkali, however, are not considered effective enough for use in relaxers. In addition to breaking the disulfide bonds, these types of relaxers also neutralize the fatty acids contained in the hair lipids, thus stripping the fatty acids from the hair.
There are two common types of alkali hair relaxers. The first type is known as a lye relaxer and prime examples contain sodium hydroxide, lithium hydroxide, or potassium hydroxide; the alkali metal hydroxides. These lye relaxers are usually supplied in cream form and are applied directly to the hair. Because of the inherent dangers to hair and skin of sodium hydroxide and other alkali metal hydroxides, lye relaxers are usually relegated to the professional sector of the hair care market.
The second type of alkali relaxer is known as a no-lye relaxer. No-lye relaxers make up the bulk of the non-professional or home use market sector. A no-lye relaxer system comprises a precursor cream which contains an alkaline earth metal hydroxide, such as calcium hydroxide, which is mixed with a liquid activator that contains a strong nitrogenous base, such as guanidine carbonate. The activator liquid and the precursor cream are mixed just prior to use. There is a chemical reaction between these components, for example, between the calcium hydroxide in the precursor cream and the guanidine carbonate in the liquid. This reaction produces the hair relaxing agent in activated form, in this case, guanidine hydroxide, which becomes the active alkali in treating the hair. A lye relaxer does not require a separate activator to produce the active relaxing agent, which is, for example, sodium hydroxide or lithium hydroxide.
All alkali relaxers are meant to be applied to the hair for a specific period of time. Then they are to be rinsed off and thereafter to be neutralized, to stop the action of the relaxer. Neutralizing is typically done using an acidic neutralizing shampoo to bring the hair back to a neutral pH. Typically, the hair is then conditioned with a leave in conditioner.
Relaxing human hair is a destructive and irritating process that is known to strip the hair of its natural fatty acids. Neutralizing shampoos that are typically used after the relaxer can further strip away the fatty acids due to their detergency effect. The hair neutralizing compositions, systems, kits and methods of the present invention avoid at least some damage caused by acidic neutralizing shampoos.